Androgen and estrogen, which are sex hormones, show a great diversity of physiological activities inclusive of differentiation and proliferation of cells. On the other hand, it has been clarified that androgen and estrogen act as an exacerbation factor in certain diseases. It is known that steroid C17,20-lyase is responsible for the final stage of the biosynthesis of androgen in the body. That is, steroid C17,20-lyase produces dehydroepiandrosterone and androstenedione using, as a substrate, 17-hydroxypregnenolone and 17-hydroxyprogesterone, which are generated by cholesterol. Therefore, a pharmaceutical agent inhibiting steroid C17,20-lyase suppresses production of androgen, as well as production of estrogen synthesized using androgen as a substrate. Such pharmaceutical agent is useful as an agent for the prevention and therapy of diseases wherein androgen and estrogen are exacerbation factors. Examples of the diseases, in which androgen or estrogen is an exacerbation factor, include prostate cancer, prostatic hypertrophy, masculinism, hypertrichosis, male-type baldness, male infant-type prematurity, breast cancer, uterine cancer, ovarian cancer, mastopathy, hysteromyoma, endometriosis, adenomyosis of uterus, polycystic ovary syndrome and the like.
Steroid type compounds and non-steroid type compounds are already known as steroid C17,20-lyase inhibitors. Steroid type compounds are disclosed in, for example, WO92/15404, WO93/20097, EP-A-288053, EP-A-413270 and the like. As non-steroid type compounds, for example, JP-A-64-85975 discloses (1H-imidazol-1-yl)methyl-substituted benzimidazole derivatives, WO94/27989, WO96/14090 and WO97/00257 disclose carbazole derivatives, WO95/09157 discloses azole derivatives, U.S. Pat. No. 5,491,161 discloses 1H-benzimidazole derivatives and WO99/18075 discloses dihydronaphthalene derivatives.
In general terms, when a compound contained in a pharmaceutical preparation as an active ingredient has an optical isomer, pharmacological actions and pharmacokinetics may be different depending on optical isomers. In this case, only one of the optical isomers is used as an active ingredient for the purpose of potentiating the activity, and therefore, for reducing the dose, or avoiding unpreferable side effects and the like. For this end, a method for selectively and efficiently producing an optically active compound is desired, wherein the most convenient method is optical resolution of racemate by liquid chromatography using an optically active column filler. When the objective compound is a basic or acidic compound, optical resolution comprising forming a diastereomeric salt by an acid-base reaction with an optically active acid or amine, and separating the salt based on the differences in properties of the both is known to be one of the industrial methods, because this method can achieve a high optical purity comparatively easily and affords production in a large scale.
The optically active acid and amine used here are reported in number as optical resolution reagents. Tartaric acid monoanilides as acidic optical resolution reagent are among them and are known to be effective for optical resolution of many basic compounds [J. Org. Chem., 33, 3993 (1968), JP-A-50-41870, JP-A-51-54566, JP-A-61-7238, JP-A-4-108773, JP-A-5-32620, JP-A-6-100502, JP-A-6-107602, JP-A-6-107604 and the like]. Tartaric acid monoanilide derivatives can be prepared by, for example, the methods described in J. Am. Chem. Soc., 70, 1352 (1948), J. Org. Chem., 33, 3993 (1968), JP-A-10-218847, JP-A-2001-89431 and the like.